1. Field of the Invention
The present invention relates generally to a seat belt system for restrainin.g an occupant of a vehicle and, more particularly, to a seat belt retractor including an energy absorbing mechanism.
2. Description of Related Art
Automobiles typically include seat belts or restraint systems for restraining a vehicle occupant in their seat during rapid deceleration of a vehicle from a cause such as a collision. Various types of seat belts or restraint systems using a seat belt retractor are commonly used. One type of seat belt retractor includes a spool or reel used to wind up and store the webbing of a seat belt. The spool or reel locks in place to prevent further unwinding of the seat belt during a rapid deceleration of a vehicle to restrain the vehicle occupant.
The retractor may include an energy absorbing mechanism such as a torsion bar that permits the spool or reel to rotate and let out an additional amount of seat belt in response to a load placed on the seat belt by the occupant. The forward motion of the occupant puts a load on the torsion bar allowing the spool or reel to rotate twisting the torsion bar whereby the restraint force on the occupant is limited by routing the forces through the torsion bar to form said predefined seat belt load.